Fuel-supplying device



March 11, 1930.

J. c. GROFF FUEL SUPPLYING DEVICE Filed Aug. 6, 1924 2 Shets$heet 1 FIG. 2.

INVENTOR w k BY QQPM 'Qi ATTORNEY? J. C GROFF FUEL SUPPLYING DEVI CE Marph 11, 1930.

2 Sheets-Sheet 2 Filed Aug. 6, 1924 In M. m M

FIG. .5.

LII.

Patented Mar. 11, 1930 JOSEPH C. GEOFF, OF NEW YORK, N. Y.

FUEL-,SUPP'LYING DEVICE Application filed August 6, 1 924. Serial N'o. 730,333.

This invention relates to improvements in internal combustion engines of the compres sion ignition type, and more particularlydt rooted to provision of improved means for 5 supplying the fuel to the combustion. cylinder. i

One object of my invention resides in the provision of an improved fuel injector forengines of this class which will inject the fuel charge without the use of spray air, and without employing a mechanically actuated fuel injection pump. Provision is made for utilizing the elastic pressure medium within the combustion cylinder to efiect airless injection 1 of the fuel, and this operation is preferably effected by a hollow fuel plunger which forms part of a differential piston device.

A further object of the present invention resides in provision of a novel arrangement of parts of the fuel admitting and regulatmg devices whereby such parts may be relatively stationary and may act to admit thefuel at 'a fixed point in the combustion cylinder, and may also be more readily associated with a co-operating combustion cylinder thereby affording a simpler and more efficient cylinder-head design.

Afurther object of'the present invention resides in the provision of means for admitting the fuel into the .combustion cylinder in sucha manner that the fuel pressure is sustained over a considerable period of fuel admission whereby constant pressure combustion conditions are more closely approached.

A further object of thepr'esent invention resides in the provision of a novel fuel spraying device whichis not only more accessible for inspection and repair than previous fuel sprayers but is also of such form that, while good penetrating characteristics of the fuel particles are retained, the distribution of the fuel spray-jets is more completely effected than heretofore. A further object of the present invention is the provision of a spray nozzle element of such character that'fuel nozzle velocities are kept at the minimum as is the temperature of the nozzle walls thereby minimizing the objectionable features of, excessive nozzle erosion and coking of the fuel heretofore present.

A further object of the present invention resides in the improvements in the fuel admitting or injecting devices to the generalend that such devices may be more accessible for adjustment and repair and capable of more prolonged and continuous operation than with previous devices of this class.

A further object of the present invention resides in the provision of means which obviates the necessity of employing an auxiliary device for building up the fuel pressure when starting up or maneuvering the engine, as heretofore required.

Further objectsand advantages will be pointe-dtout in more detail hereinafter in the accompanying specification and claims as shown in the drawings, which by way of illustration show what I now consider preferred embodiments of the invention.

In the drawings Fig. 1 shows a vertical longitudinal section of the fuel-injector'through the various cooling passa es,'and indicates the relative positions oft 1e power and fuel-injector pistons at the instant fuel admission commences. The section is taken on line ll of Fig. 3.

Fig. 2 shows a vertical longitudinal section of the fuel-injector through the various fuel passages, the section being taken on the line 2-2 of Fig. 3, and shows the relative positions of the power and fuel-injector pis- PATENT/OFFICE" tons just prior to the end of fuel admission for maximum load. i

Fig. 3 shows a top plan view of the parts shown in Fig. 1.

F ig. 4 shows artransverse section on the llne 4-4: 'in Fig. 1.

Fig. 5 shows an enlarged longitudinal vertical section of the lower portion of the 1nj ectorpiston and stationary fuelvalve casing as shown in Fig. 1.

tudinal section of the lower portion of the fuel valve casing as shown in Fig.2. The sectionv is taken substantially on .line 66 of Fi 8.

, Fig. 7 shows a bottom view of the device, the viewbeing drawn lookin 1n the direction of the arrows designated 7-7 in Fig. 5.

Figs. 8, 9 and 10 show transverse horizon- Fig. 6 shows an enlarged vertical longital sections taken on the respective lines 88, 9-9 and 10-10 of Fig. 6.

My improved fuel-injector comprises a diminutive piston 1 exposed to the pressure existing in the combustion cylinder and free in itself to reciprocate in a bored out portion of the cylinder head 22 or in parts co-operating therewith, such as in the sleeve 28 shown in Figs. 1, 2 and 4. Preferably secured to thepiston 1 is a hollow fuel plunger 2 of annular cross-scction and concentrically disposed with the pistons As shown in Figs. 1 and 2the fuel plunger 2 itself is of the differential type, which design affords a rugged means of suplying extremely small measured charges of fuel at high pressure and with sensitive regulation but devoid of delicate structure.

The hollow injector-piston-fuel-plunger passages.

. by gravity Fuel is supplied to the injector by the supply pipe 9 through the automatic inlet valve 10, under relatively low pressure either feed or by any suitable supply (not shown) measure the amount so supplied.

When the pressure of the gases in the combustion cylinder drops sufiiciently the spring 48-forccs the injector piston-plunger clement down onto the annular seat 8 provided by the sleeve 23. The shock when returning the piston 1 to the seat 8 maybe eliminated by proportioning the spring 18 in such a manner that the. return stroke occurs during the earliest portion of the expansion in thecombustion cylinder, in which the rate of pressure change is most gradual.

As soon as the injector piston 1 commences its down or return stroke the entering fuel enters the annular space 12, shown in Figs. 1, 2 and 4, created by the differential fuel plunger 2, through the inlet valve 10 and supply passage 11 The fuel continues to fiow until the injector piston has come to rest and all passages of the fuel system are filled with fuel, when the inlet valve 10 closes automatically. V

During the compression stroke of the power piston 47 the pressure in the cylinder tends to thrust the injector piston 1 upwards with gradually increasing force, but no motion of the latter is possible prior to the instant in which the fuel valve stem 5 is raised from its seat 19, since the fuel plunger 2 acts against the fuel which is a non-elastic medium. Thus up to the instant that the fuel .iiws the which may or may not valve 19 opens, the fuel pressure gradually increases in value in accordance with the increasing pressures in the combustion cylinder.

The instant that the fuel valve stem 5 is lifted from its seat 19 by means of suitable valve gear attached to the upper end of the fuel valve stem 5, but not shown in the drawfuel pressure above valve 19 acts upon the fuel remaining in the fuel passage 20 and spray nozzles 21 which were left filled from the preceding cycle and the fuel is immediately sprayed into the combustion cylinder. Thus there is but a minute motion of the injector piston 1 and hence a negligible drop in compression and ignition temperature prior to'injection of the first particles of fuel.

The fuel is discharged from the annular space 12 thru the port 13 and the passage '14 leading to the head 6 thru an annular sleeve joint 15 which is carried by the head 6, and which cooperates with the fuel cylinder body 24, as shown in Fig.2. The fuel is further body 4 and which lead to the grooves 18 provided in the valve stem 5.

An important feature arises in the location of the fuel discharge port 13, which is so situated with respect to the top of the effective portion of the differential fuel plunger 2, that when said fuel plunger has displaced a quantity of fuel corresponding to the amount required for the maximum load of that particular cylinder, further motion of the fuelplunger will cover the port 13; thereby gradually bringing the injector piston to rest should the fuel valve 19 fail to function for any reason, instead of imparting a shock which would otherwise result when the injector piston 1 is brought up against the bottom of piece 24 which forms the fuel cylinder body or fuel plunger barrel.

It is of importance to efficiently cool the surfaces of the fuel spray nozzles and cobody 4 and the casing 3 which slides over theformerwith a snug fit. These passages convey the cooling medium to and from the fuel spray nozzle element 7. in cooperation with the passages 27, 28, 29, 30 and 31 in the order mentioned, as shown in Figs. 5, 9 and 10, in this particular embodiment. The

" ceiving the packing rings 45, and which also cools .the injector piston surfaces and rings 50, by means of the plungers 34 and 36, as shown in Figs. land 4.

The various paths of the cooling medium are shown by the arrows indicated in the cooling medium passages in Fig. 1,for this particular embodimen The arrangement of the casing 3, spray element 7 secured to the former, and the fuel valve body 4' is such that flexural rigidity of the casing assembly is effected by counteracting the upward-forceson the transverse cross-section of j the spray element 7, exposed to the {pressure within the combustion cylinder, througlithe introduction of down- Ward forces creat d-by, the fuel pressure upon 1 any sultable cross-sectional area of casing 3 or any parts attached thereto. In this particular embodiment the cross-section is that of the cylindrical passage 51 with which the sleeve joint 46 (carried by the spray nozzle element 7) cooperates, as shown in Figs. 5 and 6.

' It is desirable and important if not neces-' sary to maintain the proper alignment between the spray nozzles 21 and the deflecting surfaces 38 secured to the injector piston 1. The means used to effect this are as follows: The injector piston 1 and the fuel cylinder body 24 are properly aligned by means of the dovetailed key 39, as shown in Figs. 2 and 4; the fuel valve body 4 is properly aligned with the head-6 by suitable marks when assembling same, and the head 6 is aligned with the body 24 and hence with the injector piston 1 by means of the sleeve ,joint 15; the fuel nozzles 21 are properly aligned by means of the winged sleeve 40, shown in Figs. 5, 6, 9 and 10, which cooperates with the transverse grooves 41 and 42 in the valve body 4 and spray nozzle element 7 respectively.

The spraynozzle element -7 is first tightly screwed into the threaded portion of the casing 3 and the winged sleeve 40 inserted so as to cooperate withthe transverse grooves 42 in spray element 7, which were previously aligned with that set of,diametrically opposed longitudinal grooves 43 in casing 3' thereby permitting a tight screwed joint between casing 3 and spray'element 7. Thecasing 3 is then slipped over the fuel body 4 and turned so as to match and engage the grooves 41 with the upper edges ofthe winged sleeve 40., The casing 3 is then secured to the head 6 by means of the sleeve nut Thus the Winged sleeve has three functions to perform, in that it maintains the proper alignment between the spray nozzles 21 and the deflecting surfaces 38, it acts as a locking device to prevent dislodgment of the spray element 7 from the casing 3, and it also maintains separation of the inlet and discharge passages for: the cooling medium thereby insuring positive circulation. Suflicient clearance between these grooved joints permit free and independent longitudinal expansion of the casing 3 or valve stem body 4 due to the employmentof the sleeve joint 46 betweenthe spray element 7 and the source of fuel supply, which also obviates the necessity of employing the double packed joint heretofore used. I 4,

The fuel valve stem 5 is returned and held on its seat .19 by the spring 37 In the present embodiment of theinvention the size of the fuel charge is varied to conformwith the load on "the engine by varying the time ele-' ment during which said valve 19 is open through use of suitable valve regulating mechanism (not shown in the-drawings).

An alternative method is to vary the down or return stroke of the fuel plunger, by securing, any suitable annular stop to the upper end of the ineffective portion of the hollow differential fuel plunger so as to cooperate with any adjustable annular seat capable of vertical adjustment, and it is intended that this method be employed in small quick running engines. 7

The fuel spray jets 49 emitted from the spray nozzles 21 impinge tangentially upon suitably curved deflecting surfaces 38 attached to the injector piston 1, as shown in Figs. 5 and 7, and by virtue of the relative motion which exists between the latter and the fixed spray nozzle element 7 various angles of deflection are brought into play thereby promoting better distribution of the fuel particles throughout the combustion chamber. The deflecting surfaces in cooperation with the injector piston 1 are so disposed that the direction of the fuel jets into I the combustion chamber is made to conform V I with the instantaneous shape of the combustion chamber, which varies as the power plston 47 recedes during fuel admission. Figs.

1 and 2 show-the relative positions of the injector piston 1, power piston 47, and the general direction of the fuel jets at the start and prior to the end of fuel admission respecof valve 19.

formly sustained and mechanically independent of the timing and period of opening This permits lengthening of the period of fuel admission and hence diminishing the rate of admission thereby effecting constant pressure combustion for the maximum load at rated speed. The same constant pressure combustion conditions prevail at fractionalloads at the same rated speed by terminating the admission period sooner.

I do not wish to rigidly confine myself to the various details of this particular embodiment shown and described as it'will be readily apparent to any one skilled in the art that various elements may be varied without departing from the broad scope of the invention. For instance, a simple hollow fuel plunger might be used in cooperation with a fixed concentric casing using any desired form of pressure joint between same. And also the fuel might be supplied to the casing in other ways such as'by means of ports through the walls of the hollow differential fuel plunger, which ports would act in conjunction with registering ports in the walls of the stationary casing and a sliding pressure joint between the inner surfaces of the hollow plunger and the outer surfaces of the casing.

What I claim is 1. A fuel supplying system for interna --combustion engines of the compression ignitiontype comprising in combination, fuel injecting means comprising a differential piston device operated by the pressure developed within the power cylinder, and means comprising a member extending entirely through hollow portions of said piston into the combustion cylinder and fixed against motion upon the relative movement of said piston for immediately injecting the fuel upon and by the initial displacement of the diiferential piston device.

2. A .fuel supplying system for internal combustion engines of the compression ignition type comprising in combination, a differential piston device operated by the pressure developed in the power cylinder, a hollow plunger connected to the differential piston device and concentrically disposed thereto, fixed means cooperating with and traversing said hollow plunger, a fuel valve associated with said fixed means and a spray nozzle element carried by said fixed means.

3. A fuel supplying system for internal combustion engines of the compression ignition type comprising in combination, a differential piston device operated by the pressure developed in the power cylinder, a hollow plunger connected to the differential piston device and moved thereby, a relatively stationary casing concentrically disposed with respect to said hollow plunger, a fuel valve gulded within said casing, and a spray nozzle device also carried by said casing whereby the nozzle device is at all times in a fixed position relative to the power cylinder. 4. A fuel supplying system for internal combustion engines of the compression ignition type comprising in combination, a differential piston device operated by the pressure developed in the power'cylinder, a hollow fuel plunger connected to the differential piston device and moved thereby, a relatively stationary casing traversing said hollow plunger and carrying a spray nozzle element, and cooling passages in said casing to provide positive circulation passages of cooling medium to and from said spray element. A fuel supplying system for internal combustion engines of the compression ignition type comprising in con'ibination a differential piston device operated by the pressure developed in the power cylinder, a hollow fuel plunger, a relatively stationary casing traversing said hollow plunger and carrying a spray nozzle-element in which cooling passages are provided in and around the spray nozzles.

6. A fuel supplying system for internal combustion engines of the compression ignition type comprising in combination, a differential piston device operated by the pressure developed in the power cylinder, a hollow fuel plunger, a relatively stationary casing traversing said hollow plunger and supporting a spray nozzle element, and means for supplying fuel and cooling medium there to, said supporting casing and spraynozzle element being connected with a plurality of joints, one of said joints being freely adjust- .able irrespective of the other joint for the purpose described.

7. A fuel supplying system for internal combustion engines of the compresison ignition type comprising in combination, a differential piston device operated by the pressure developed in the power cylinder, a fuelinjection device, a spray nozzle associated therewith, a cooperating deflector provided witha plurality of variously disposed deflecting surfaces adapted to deflect the fuel spray jets through various angles, and means for effecting a relative movementof said deflector with respect to the spray nozzle to bring various angles of deflecting surface into cooperation with the jet or spray.

8. A fuel supplying s stem for internal nition type comprising in combination, a differential piston device operated by the pressure developed in the power cylinder, a hollow fuel plunger cooperating with a relatively stationary easing concentrically discasing.

9. A fuel supplying system for internal combustion engines of tie compression ignition type comprising in combination, a differential piston device operated by the pressure developed in the power cylinder, a hollow fuel plunger cooperating with a relatively stationary and concentrically disposed casing, a fuel injection device, a spray nozzle associated therewith, a deflector provided with suitably curved deflecting surfaces for deflecting the spray jets in various directions,

and means for malntaining proper alignment between the said spray nozzle and deflecting surface and parts cooperating therewith, in the manner described.

10. A fuel supplying system for internal combustion engines of the compression ignition type comprisingin combination, a diflerential piston device operated by the pressure developed. in the power cylinder, a hollow fuel plunger, a relatively stationary and concentrically disposed casing cooperating therewith, a detachable spray nozzle element carried thereby, said spray nozzle element having fuel and cooling medium supply passages, and means for balancing the pressures reacting upon the casings to eliminate harmful compressive stresses therein substantially as described.

11. A fuel supplying system for internal combustion engines of the compression ignition type comprising in combination, a fixed element, a hollow piston forming the actuating member of a differential piston device and operated by the compressed medium in the power cylinder, and means fixed with respect to said fixed element and traversing entirely through said hollow piston for admitting the fuel into the-power cylinder.

' nition type comprising in combination, a hol- 12. A fuel supplying system for internal combustion engines of the compression iglow differential piston device actuated by the pressure developed within a power cylinder, a hollow plunger device coacting therewith for pumping the fuel, and means extending through said hollow plunger and fixed against movement relative to the movable piston device for conveying the fuel from the pump ing device to the power cylinder.

In testimony whereof I hereto afiix my signature. r I

JOSEPH C. GEOFF. 

